The ability to successfully translate basic research in leukemia to the clinical setting, as well as to better understand the relevance of observed clinical phenomena through laboratory-based research, is greatly facilitated by the availability of an extensive repository of tissue samples, with accompanying complete pathologic and clinical data, procured from leukemia patients. The OSUCCC Leukemia Tissue Bank Shared Resource (LTBSR), separate and distinct from the CALGB Leukemia Tissue Bank, is a shared resource established in 1997 with over 4,500 patient samples procured from 762 consented leukemia patients at OSU. The infrastructure of the OSUCCC LTBSR is well-established and is directly under our leadership. Specifically we have a large leukemia tissue repository, including both leukemic tissue and normal tissue germ line DNA, accompanied in all cases with complete pathologic, cytogenetic and clinical data for ready correlation of clinical and biological results. In addition, all the essentials of effective leukemia tissue bank management, including the activities of tissue collection, quality control of specimens, tissue storage, procurement of initial and follow-up samples and their pathology and clinical information, data entry and database management, and patient consent and confidentiality are very well developed. Furthermore, the procedures for prioritizing and distributing tissue to a large base of investigators within the OUCCC are effectively in place. Finally, our success in managing this large leukemia tissue resource can be seen in the documented sample collection for and sample distribution to all leukemia researchers within the CCC and 28 publications where the OSUCCC LTBSR has played a significant role. Against this background, we believe that this Shared Resource will function well in the support of the research mission of the OSUCCC in )roducing high-quality basic and clinical research in hematological malignancy. Currently the OSUCCC _TBSR is funded solely with OSUCCC/institutional support. The Specific Aims of this Shared Resource are, therefore, to: 1) Continue to provide a central collection, processing and a state-of-the-art repository for samples collected from leukemia patients treated on OSU protocols, and 2) Provide materials from the LTBSR to interested investigators within OSUCCC, as well as to outside interested investigators involved in collaborative studies with OSU, who examine relevant cellular and molecular properties of leukemia.